System and method for network topology and flow visualization

ABSTRACT

A topology view of a network is generated on a visual display of a computer system. The topology view includes subnet objects, network device objects, and interface objects within the network device objects. Network flow records are acquired from each device within the network. Separate network flow records acquired from different devices in the network are correlated together into a common network flow record. Each of the separate network flow records shares a common source address and a common destination address. The common network flow record specifies transmission path segments of a communication through the network. The common network flow is rendered in the visual display over the topology view of the network by displaying an arrow for each transmission path segment traversed by the communication through the network.

CLAIM OF PRIORITY

This application is a continuation-in-part application under 35 U.S.C.120 of prior U.S. application Ser. No. 12/336,433, filed Dec. 16, 2008now U.S. Pat. No. 7,975,190, entitled “System and Method for NetworkDevice Configuration,” which is a continuation application under 35U.S.C. 120 of prior U.S. application Ser. No. 11/483,054, filed Jul. 6,2006 now U.S. Pat. No. 7,500,158, entitled “System and Method forNetwork Device Configuration.” The disclosures of the above-identifiedapplications are incorporated in their entirety herein by reference.

U.S. GOVERNMENT LICENSE

The U.S. Government has a paid-up license in this invention and theright in limited circumstances to require the patent owner to licenseothers on reasonable terms as provided for by the terms of Contract No.N00014-07-C-0542 awarded by The Office of Naval Research.

BACKGROUND

In today's highly networked world, it is important for computer andnetwork professionals to have knowledge of network hardware and softwareconfigurations, network connections, and how data flows through thenetwork under various conditions. A given network may include a verylarge number of diverse network devices. Such network devices mayinclude, but are not limited to, routers, network hubs, switches,repeaters, network interface cards, and other related networkinginfrastructure. Therefore, it should be appreciated that obtaining anaccurate global understanding of a given network's configuration andperformance can be quite challenging. Also, in order to increaseefficiency, bandwidth, and functionality of a given network, it isnecessary to have a global understanding of how the given network isconfigured and how data traverses through the given network. Moreover,as new network devices are introduced into a given network, networkmanagement professionals are strained to understand how introduction ofthe new network devices may impact network operation, quality of service(QoS), and other aspects of network performance.

SUMMARY

In one embodiment, a method is disclosed for visualizing a networktopology. The method includes acquiring device configuration data from anumber of network devices through which network flows are to betransmitted. The acquired device configuration data is analyzed toidentify one or more interfaces of each of the number of networkdevices, and to identify subnets to which the one or more interfacesconnect. The method includes rendering in a visual display of a computersystem a number of device objects corresponding to the number of networkdevices. Also, a number of interface objects are rendered in the visualdisplay within each of the number of device objects. Each interfaceobject represents a particular identified interface of the networkdevice that corresponds to the rendered device object. The method alsoincludes rendering in the visual display a number of subnet objectscorresponding to the identified subnets. Line segments are rendered inthe visual display to extending between interface objects and subnetobjects. The line segments represent network connections over whichnetwork flows are to be transmitted.

In another embodiment, a method is disclosed for visualizing a networkflow over a network topology. The method includes an operation forgenerating a topology view of a network on a visual display of acomputer system. The topology view includes subnet objects, networkdevice objects, and interface objects within the network device objects.The method also includes an operation for acquiring network flow recordsfrom each device within the network. The method further includes anoperation for correlating separate network flow records acquired fromdifferent devices in the network together into a common network flowrecord. Each of the separate network flow records shares a common sourceaddress and a common destination address. The common network flow recordspecifies transmission path segments of a communication through thenetwork. The method also includes an operation for rendering in thevisual display the common network flow over the topology view of thenetwork by displaying an arrow for each transmission path segmenttraversed by the communication through the network.

In another embodiment, a system for visualizing a network flow over anetwork topology is disclosed. The system includes a device informationmanagement module defined to acquire device configuration data from anumber of devices within a network. The system also includes a networkvisualization module defined to analyze the acquired deviceconfiguration data to identify one or more interfaces of each of thenumber of devices, and to identify subnets to which the one or moreinterfaces connect. The network visualization module is further definedto render in a visual display a topology view of the network includinggraphical representations of the devices, interfaces within the devices,and connections between the interfaces and subnets. The system alsoincludes a network flow collection management module defined to acquirenetwork flow records from each device within the network. The systemalso includes a network flow correlation module defined to correlateseparate network flow records acquired from different devices in thenetwork together into a common network flow record. Each of the separatenetwork flow records shares a common source address and a commondestination address. The common network flow record specifiestransmission path segments of a communication through the network. Thenetwork visualization module is further defined to render in the visualdisplay the common network flow over the topology view of the network bydisplaying an arrow for each transmission path segment traversed by thecommunication through the network.

Other aspects of the invention will become apparent from the followingdetailed description, taken in conjunction with the accompanyingdrawings, illustrating by way of example the principles of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration showing a flowchart of a method for generatinga network device knowledge database, in accordance with one embodimentof the present invention;

FIG. 2 is an illustration showing a test system, in accordance with oneembodiment of the present invention;

FIG. 3 is an illustration showing an exemplary table of test caseinformation and associated results, in accordance with one embodiment ofthe present invention;

FIGS. 4A through 4E are illustrations showing an alternativerepresentation of test case information and associated results, inaccordance with one embodiment of the present invention;

FIG. 5A is an illustration showing an exemplary knowledge databaseschema with test results data populated therein, in accordance with oneembodiment of the present invention;

FIG. 5B is an illustration showing an extension of the knowledgedatabase schema of FIG. 5A to include best practices data, in accordancewith an exemplary embodiment of the present invention;

FIG. 5C is an illustration showing an extension of the knowledgedatabase schema of FIG. 5A to include historical data, in accordancewith an exemplary embodiment of the present invention;

FIG. 6 is an illustration showing the interactions between the testsystem, the network test engineer, and the knowledge database, inaccordance with one embodiment of the present invention;

FIG. 7 is an illustration showing a flowchart of a method for optimallyconfiguring a network device by utilizing the knowledge databasedeveloped according to the method of FIG. 1;

FIG. 8 is an illustration showing the interactions present in performingthe device configuration process described in the method of FIG. 7, inaccordance with one embodiment of the present invention;

FIG. 9 is an illustration showing a logical representation of thenetwork configuration tool and the network monitoring tool, asimplemented in performing the method of FIG. 7, in accordance with oneembodiment of the present invention;

FIG. 10 is an illustration showing the interactions present inperforming the testing/verification process described in the method ofFIG. 7, in accordance with one embodiment of the present invention;

FIG. 11 shows a system for visualizing a network topology and networkflows over the network topology, in accordance with one embodiment ofthe present invention;

FIG. 12 shows an example device information table that may be generatedby the device information management module, in accordance with oneembodiment of the present invention;

FIG. 13 shows an example network topology visualization within agraphical user interface (GUI) of the system, in accordance with oneembodiment of the present invention;

FIG. 14 shows an example device flow table, in accordance with oneembodiment of the present invention;

FIG. 15 shows an example global flow table based on the example deviceflow table of FIG. 14, in accordance with one embodiment of the presentinvention;

FIG. 16A shows an example of the GUI depicting common networkcommunication flows over the topology view in the first display region,in accordance with one embodiment of the present invention;

FIG. 16B shows an example of how a particular network communication flowcan be selected and identified within the GUI, in accordance with oneembodiment of the present invention;

FIG. 16C shows an example of how the GUI can be operated to zoom in on aparticular network device, in accordance with one embodiment of thepresent invention;

FIG. 16D shows an example of how the GUI can be operated to display adevice level view of a particular network device, in accordance with oneembodiment of the present invention;

FIG. 17A shows a control GUI for defining, saving, and applying anetwork flow parameter filter, in accordance with one embodiment of thepresent invention;

FIGS. 17B-17F show control GUIs for applying selected colors toparticular network topology and flow parameter ranges to facilitatevisual evaluation of the network and flows therein, in accordance withvarious embodiments of the present invention;

FIG. 18 shows a flowchart of a method for visualizing a networktopology, in accordance with one embodiment of the present invention;and

FIG. 19 shows a flowchart of a method for visualizing a network flowover a network topology, in accordance with one embodiment of thepresent invention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itwill be apparent, however, to one skilled in the art that the presentinvention may be practiced without some or all of these specificdetails. In other instances, well known process operations have not beendescribed in detail in order not to unnecessarily obscure the presentinvention.

It should be appreciated that the present invention can be implementedin numerous ways, including as a process, an apparatus, a system, adevice, or a method. Several exemplary embodiments of the invention willnow be described in detail with reference to the accompanying drawings.

FIG. 1 is an illustration showing a flowchart of a method for generatinga network device knowledge database, in accordance with one embodimentof the present invention. The method begins with an operation 101 forcreating a test system for a network device. The network device canrepresent any type of device through which data traffic is transferredduring network communication. For example, in one embodiment the networkdevice is a router.

FIG. 2 is an illustration showing a test system 200 created in theoperation 101, in accordance with one embodiment of the presentinvention. The test system 200 includes a device under test (DUT) 205connected to receive data communications from a network control tool 201and a test generator 203, as indicated by arrows (1.1) and (1.2),respectively. In one embodiment, the DUT 205 is a router. However, itshould be appreciated that the DUT 205 can also be any type ofnetworking device other than a router. Additionally, in one embodiment,rather than the DUT 205, a system under test (SUT) is connected withinthe test system 200, wherein the SUT can represent any combination ofnetwork devices. For ease of description, the test system 200 will bedescribed hereafter as including the DUT 205.

The network control tool 201 is a software module defined to enable auser, e.g., a network test engineer, to apply a configuration to the DUT205. One example of the network control tool 201 is a configurationinterface uniquely associated with the DUT 205. When the test system 200is utilized to perform a particular test on the DUT 205, the user canuse the network control tool 201 to configure the DUT 205 in a mannerappropriate for the particular test to be performed. In one embodiment,the DUT 205 is capable of being configured in multiple ways. Therefore,the test results obtained from the test system 200 will be correlated tothe particular configuration of the DUT 205 when the test is performed.Thus, it should be appreciated that configuration of the DUT 205 throughthe network control tool 201 can be considered as a test input.

The test generator 203 is a hardware and/or software module defined toapply network input to the DUT 205. In one embodiment, the network inputtakes the form of data communication, i.e., network traffic, for whichthe handling performance thereof by the DUT 205 is of interest. The testgenerator 203 is capable of simultaneously generating any number ofnetwork traffic threads to be processed as network input by the DUT 205.For example, if a test is defined to investigate how the DUT 205 handlesmultiple types of network traffic, the test generator 203 can beprogrammed to simultaneously generate the multiple types of networktraffic.

The test system 200 further includes a test analyzer 207 and a networkmonitoring tool 209, which are each connected to receive data from theDUT 205, as indicated by arrows (1.3) and (1.4), respectively. The testanalyzer 207 is a hardware/software module defined to record the outputfrom the DUT 205. In one embodiment, the output recorded by the testanalyzer 207 takes the form of network communication data that would beoutput from the DUT 205 based on both the network traffic generated bythe test generator 203 and the DUT 205 configuration set through thenetwork control tool 201. The test analyzer 207 is defined to analyzethe recorded output from the DUT 205 to determine various networkmetrics such as jitter, output rate, latency, bit errors, packet drops,reorder instances, fragmentation instances, among others. In addition tothe specific network metrics identified above, it should be understoodthat the test analyzer 207 can be defined to determine essentially anyother type of network metric.

The network monitoring tool 209 is a hardware/software module defined tomonitor the internal operations of the DUT 205 during test performance.In one embodiment, the network monitoring tool 209 functions to recordthe state of the DUT 205 during test performance based on the statemonitoring capabilities afforded by the DUT 205. In various embodiments,the network monitoring tool 209 can be defined to record device metricssuch as CPU usage, memory usage, pre-policy rate, post-policy rate,queue depth, packet drops, among others. In addition to the specificdevice metrics identified above, it should be understood that thenetwork monitoring tool 209 can be defined to determine essentially anyother type of device metric.

Returning to the method of FIG. 1, following creation of the test system200 for the network device, i.e., DUT 205, the method proceeds with anoperation 103 for creating test cases to be performed on the networkdevice. In one embodiment, the test cases are created manually by anetwork test engineer. In another embodiment, the test cases can becreated automatically based on a set of general specifications providedby a network test engineer. Each test case is defined based on both theconfiguration of the DUT 205 as established through the network controltool 201, and the network traffic provided as input to the DUT 205 fromthe test generator 203. In the embodiment where the DUT 205 is a router,the configuration can be characterized by the following parameters:router model number, router operating system, router hardware, memorytype and size, router policy, etc. Also, in the embodiment where the DUT205 is a router, the input network traffic can be characterized by thefollowing parameters: packet type, packet length, source port,destination port, data rate, data flow characteristics, etc.

Following the operation 103, the method proceeds with an operation 105for exercising the test system 200 to generate the test resultscorresponding to the test cases created in operation 103. FIG. 3 is anillustration showing an exemplary table of test case information andassociated results obtained by performing operations 101 through 105, inaccordance with one embodiment of the present invention. It should beunderstood that the test case information and results presented in FIG.3 are provided for exemplary purposes only and are not intended torepresent/provide any restrictions on the types of test cases that maybe performed using the present invention.

FIG. 3 shows a test case “Case 1” performed on a “Cisco 871” router.Test case “Case 1” actually represents three separate tests identifiedby “Time 0,” “Time 1,” and “Time 2,” wherein each test corresponds to aparticular router configuration and a particular type/combination ofnetwork input traffic. The test performed at “Time 0” is based on arouter configured to have three input queues corresponding to quality ofservice (QoS) Class A, Class B, and Class C, respectively. Class A isspecified as a priority queue having a minimum bandwidth guarantee of100 Kbps and a policer bandwidth of 110 Kbps. Class B is specified as aclass-based queue having a minimum bandwidth guarantee of 200 Kbps and apolicer bandwidth of 210 Kbps. Class C is specified as anotherclass-based queue having a minimum bandwidth guarantee of 300 Kbps and apolicer bandwidth of 310 Kbps. The router configurations for the testsperformed at “Time 1” and “Time 2” are specified in a manner similar tothat described above for the “Time 0” test.

During the performance of the “Time 0” test, UDP-RTP packets of 300 bytefixed length are transmitted from the test generator 203 to the Class Apriority queue at a rate of 125 Kbps. Also, during the performance ofthe “Time 0” test, TCP-Telnet packets of 500 byte fixed length aretransmitted from the test generator 203 to the Class B priority queue ata rate of 150 Kbps. Also, during the performance of the “Time 0” test,TCP-HTTP packets of 1000 byte fixed length are transmitted from the testgenerator 203 to the Class C priority queue at a rate of 175 Kbps. Theinput network traffic for the tests performed at “Time 1” and “Time 2”are specified, generated, and transmitted in a manner similar to thatdescribed above for the “Time 0” test.

During the performance of each test, the network monitoring tool 209 isoperated to monitor the router CPU usage, memory usage, pre-policy rateon each input queue, and post-policy rate on each input queue. Forexample, during the performance of “Time 0” test, the network monitoringtool 209 records a CPU usage of 23% and a memory usage of 7%. Thenetwork monitoring tool 209 confirms that the pre-policy rate on each ofthe QoS Class A, B, and C queues is 125 Kbps, 150 Kbps, and 175 Kbps,respectively. During the performance of “Time 0” test, the networkmonitoring tool 209 also records the actual post-policy rate on each ofthe Class A, B, and C queues as 110 Kbps, 150 Kbps, and 175 Kbps,respectively. For the tests performed at “Time 1” and “Time 2,” therouter (DUT 205) is also monitored through the network monitoring tool209 in a manner similar to that described above for the “Time 0” test.

During the performance of each test, the test analyzer 207 is operatedto record and analyze the router (DUT 205) output, including jitter,output rate, and latency. For example, during the performance of “Time0” test, the jitter, output rate, and latency for the Class A queue isanalyzed as 100 ns, 125 Kbps, and 8 ms, respectively. Also, during theperformance of “Time 0” test, the jitter, output rate, and latency forthe Class B queue is analyzed as 250 ns, 150 Kbps, and 10 ms,respectively. Similarly, during the performance of “Time 0” test, thejitter, output rate, and latency for the Class C queue is analyzed as250 ns, 175 bps, and 10 ms, respectively. For the tests performed at“Time 1” and “Time 2,” the router (DUT 205) output is recorded andanalyzed with the test analyzer 207 in a manner similar to thatdescribed above for the “Time 0” test.

It should be appreciated that the specific characterizing parameters forthe router configuration and test generator as presented in FIG. 3 arenot intended to represent an inclusive set of characterizing parameters.For example, depending on the particular network device, there may beadditional configuration parameters specified. Also, in some embodimentsthe input network traffic may be characterized by more parameters thantype, rate, and length. Furthermore, those skilled in the art shouldappreciate that the internal operation of various network devices can becharacterized in terms of parameters other than CPU usage, memory usage,pre-policy rate, and post-policy rate. Therefore, it should beunderstood that the router monitoring parameters presented in FIG. 3 arenot intended to represent an inclusive set of network device monitoringparameters. Similarly, those skilled in the art should appreciate thatthe output of various network devices can be analyzed in terms ofparameters other than jitter, output rate, and latency. Therefore, itshould be understood that the test analyzer parameters presented in FIG.3 are not intended to represent an inclusive set. Further, those skilledin the art should appreciate that the network device can easily besubstituted by a system.

In addition to the foregoing, it should be appreciated that the testresults generated in operation 105 of the method can be managed in aform different from that explicitly presented in FIG. 3. For example,FIGS. 4A through 4E are illustrations showing an alternativerepresentation of test case information and associated results obtainedby performing operations 101 through 105 of the method of FIG. 1, inaccordance with one embodiment of the present invention.

Returning to the method of FIG. 1, the method proceeds with an operation107 for storing the test results generated in the operation 105 in aknowledge database. It should be appreciated that the knowledge databasecan be defined using essentially any type of database software thatsupports a query function. For example, in one embodiment, the knowledgedatabase is implemented as an SQL database. In various embodiments, theknowledge database can be defined to include all or a portion of thetest results generated in operation 105. Additionally, in oneembodiment, the raw test results generated in operation 105 can beconsolidated through an analytical and/or comparative process to obtainan abridged version of the test results to be stored in the knowledgedatabase. Also, the schema of the knowledge database is defined toaccommodate the test results in a form required to support subsequentquery operations.

FIG. 5A is an illustration showing an exemplary knowledge databaseschema with test results data populated therein, in accordance with oneembodiment of the present invention. The knowledge database schemaprovides fields for database entry number, router model, routeroperating system, router interface, forwarding limits on input,forwarding limits on CPU, CPU usage based input rate, and outputbehavior. As a function of input rate, the output behavior can bespecified as queue depth, queue type, jitter, and latency. It should beappreciated that the knowledge database schema of FIG. 5A does notinclude all the information that is available in the raw test resultsfrom operation 105. For example, the correlation between output behaviorand queue structure is not provided in the schema of FIG. 5A. Thus, FIG.5A represents an example of the knowledge database wherein the raw testresults generated in operation 105 have been consolidated through ananalytical and/or comparative process to obtain an abridged version ofthe test results to be stored in the knowledge database. The abridgedversion of the test results as represented by the knowledge databaseschema is defined based on a target application of the knowledgedatabase. For example, the exemplary knowledge database of FIG. 5A isdefined based on the consideration that dependencies between outputbehavior and queue structure is not significant for the targetapplication of the knowledge database.

In addition to storing the test results in the knowledge database, themethod also includes an operation 109 for storing supplementalinformation in the knowledge database. In one embodiment, thesupplemental information can include additional information regardingbest practices for network configuration, which may include limitationsfor the particular configuration for the particular network device, andsampled data for network operation. FIG. 5B is an illustration showingan extension of the knowledge database schema of FIG. 5A to include bestpractices data, in accordance with an exemplary embodiment of thepresent invention. As shown in FIG. 5B, the best practices schema isdefined as a list of “rules.” However, it should be appreciated thatother embodiments can implement alternate schemas for the best practicesportion of the knowledge database. FIG. 5C is an illustration showing anextension of the knowledge database schema of FIG. 5A to includehistorical data, i.e., sampling data over time, in accordance with anexemplary embodiment of the present invention. In one embodiment, thehistorical data is entered into the knowledge database according to aschema having correlated entries for application protocol, communicationtype, average data rate as percent of 100 Mbps, and peak data rate aspercent of 100 Mbps. As with the best practices schema, it should beappreciated that other embodiments can implement alternate schemas forthe historical data portion of the knowledge database.

FIG. 6 is an illustration showing the interactions between the testsystem 200, the network test engineer 101, and the knowledge base 601 inperforming the operations 107 and 109, in accordance with one embodimentof the present invention. The raw test data having been recorded andanalyzed by the test analyzer 109 is processed according to therequirements of the knowledge database schema and is entered into theknowledge database 601, as indicated by arrow (2.1). The raw test datahaving been recorded and analyzed by the test analyzer 109 is processedaccording to the requirements of the knowledge database schema and isentered into the knowledge database 601, as indicated by arrow (2.1).The data having been recorded by the network monitoring tool 111 is alsoprocessed according to the requirements of the knowledge database schemaand is entered into the knowledge database 601, as indicated by arrow(2.2). Additionally, the network test engineer 101 directs entry of thebest practices for network configuration and historical data into theknowledge database 601, as indicated by arrow (2.3).

According to one embodiment of the present invention, FIG. 7 is anillustration showing a flowchart of a method for optimally configuring anetwork device by utilizing the knowledge database developed accordingto the method of FIG. 1. The method begins with an operation 701 forinstalling a network device in a network. In one embodiment, the networkdevice is a router. However, it should be appreciated that the networkdevice can also be any type of networking device other than a router.For the knowledge database to be directly applicable in providinginformation for optimally configuring the network device, the networkdevice installed in operation 701 should correspond to the DUT 205 orSUT analyzed in the test system 200 to populate the knowledge database.However, in some embodiments, the network device installed in operation701 may differ from the DUT 205 analyzed in the test system 200, butremain sufficiently similar to the DUT 205 such that the knowledgedatabase content is sufficiently applicable to the network device.

The method proceeds from the operation 701 to an operation 703 in whicha network engineer uses a network configuration tool to decide onnetwork settings/goals for the network device installed in operation701. Examples of the network settings/goals can include the variousnetwork traffic types expected to be handled by the network device, thelatency goal for network traffic type, and the loss goal for eachnetwork traffic type, among others. The network setting/goals may beconsidered as an establishment of criteria to be satisfied by a QoS tobe implemented within the network device.

The method proceeds from the operation 703 to an operation 705 in whichthe network configuration tool accesses the knowledge database totranslate the network settings/goals from operation 703 intoconfiguration information for the network device. In one embodiment, thenetwork configuration tool will use the knowledge database content toformulate different configuration scenarios and choices that willsatisfy the user-supplied network settings/goals. For example, thenetwork configuration tool may use the best practices content of theknowledge database to define an input queue that is appropriate for eachof the network traffic types expected to be handled by the networkdevice. In one embodiment, the input queues are defined by queueclassification, minimum bandwidth guarantee, and policing (maximum)bandwidth. For example, based on the best practices content of theknowledge database, the network configuration tool may allocate apriority queue classification to an input queue defined to handlereal-time voice network traffic. Also, based on the best practicescontent and the historical data content of the knowledge database, thenetwork configuration tool may allocate a minimum bandwidth guaranteevalue and a policing bandwidth value to each of the defined inputqueues.

The network configuration tool also functions to provide predictednetwork device performance data for each input queue defined by thenetwork configuration tool. For example, for each defined input queue,the network configuration tool will allow a user to select a networktraffic input rate, e.g., Kbps. Then, the network configuration toolwill query the test results content of the knowledge database todetermine network device performance data associated with the selectednetwork traffic input rate. Examples of the types of network deviceperformance data include latency, packet loss, jitter, packet reorderinstances, bit error instances, and fragmentation instances, amongothers. By selecting different network traffic input rates for eachinput queue, the user (network engineer) can investigate how the networkdevice will perform in handling each type of expected network traffic,given the input queue structure and QoS recommended by the networkconfiguration tool.

Following the operation 705, the method proceeds with an operation 707for selecting an optimized configuration for the network device based onthe recommended settings and predicted results provided by the networkconfiguration tool for the user-supplied network settings/goals. In oneembodiment, the method proceeds from the operation 707 to an operation709 for saving the selected network device configuration to a persistentstorage device. The network device configuration information on thestorage device can then be transmitted to another location where theactual network device is to be installed and configured. In anotherembodiment, the method proceeds from the operation 707 to an operation711 for sending the selected network device configuration to the networkdevice, such that the network device is configured accordingly.

Following operation 711, the method proceeds with a series of operationsfor performing verification and testing of the configured networkdevice. In an operation 713, test traffic is transmitted through thenetwork device. In one embodiment, the configured network device resideswithin a network that includes other devices that are capable ofgenerating test traffic. In this embodiment, the network engineerperforms operation 713 by programming one or more devices in the networkto transmit test traffic through the configured network device to beverified and tested. In another embodiment, the verification and testingcan be performed using normal network traffic transmitted through theconfigured network device to be verified and tested. In this embodiment,it is not necessary for the network to include devices that have thetest traffic generation capability.

As the test traffic or normal network traffic is transmitted through theconfigured network device, an operation 715 is performed to record astate of the network device that is being verified and tested. In oneembodiment, the state of the network device is recorded using thenetwork monitoring tool 111, previously described with respect to thetest system 200 of FIG. 1. In this embodiment, the network monitoringtool 111 will retrieve appropriate measurement data from the networkdevice. Then, an operation 717 is performed to display the test results,i.e., measurement data retrieved from network device, to the networkengineer. In an alternate embodiment, the test results can be stored ina persistent storage device for later review and analysis.

The method proceeds with a decision operation 719 for determiningwhether the test results from operation 715 match the expected behaviorof the network device under test. If the test results do not demonstratethat the network device is behaving as expected, an operation 721 isperformed to troubleshoot the discrepancy between the observed andexpected network device behavior. The troubleshooting operation 721directs the method back to operation 703 in which the network engineeruses the network configuration tool to decide on network setting andgoals. If the test results indicate that the network device is behavingas expected, the network device is considered to be optimally configuredand the method concludes.

FIG. 8 is an illustration showing the interactions present in performingthe operations 701 through 711 of the method of FIG. 7, in accordancewith one embodiment of the present invention. The network configurationtool 801 is defined to receive input from the network engineer 101, asindicated by arrow (3.1). For example, in performing operation 703, thenetwork engineer 101 will provide the settings and goals for the networkdevices 803A, 803B, and 803C to the network configuration tool 801.Also, the network configuration tool 801 is defined to provide feedbackto the network engineer 101, as indicated by arrow (3.3). For example,in performing operation 705, the network configuration tool 801 willprovide to the network engineer 101 the predicted network deviceperformance data for each defined input queue.

Additionally, in performing operation 705, the network configurationtool 801 will access the knowledge database 601, as indicated by arrow(3.2). According to operation 705, once the network device configurationis selected, the configuration data can be stored in the persistentstorage device 805, as indicated by arrow (3.5). Also, according tooperation 711, the selected network device configuration data can beused to configure each of the network devices 803A, 803B, and 803C, asindicated by arrows (3.4). Although the example of FIG. 8 indicatesconfiguration of three network devices 803A, 803B, and 803C, it shouldbe appreciated that the method of FIG. 7 is not limited to use inconfiguring a specific number of network devices. More specifically, themethod of FIG. 7 can be implemented to configure one or more networkdevices in either a parallel or serial manner.

FIG. 9 is an illustration showing a logical representation of thenetwork configuration tool 801 and the network monitoring tool 111, asimplemented in performing the method of FIG. 7, in accordance with oneembodiment of the present invention. The network engineer 101 is capableof interfacing with the network configuration tool 801 and the networkmonitoring tool 111 through a user interface 901. The networkconfiguration tool 801 includes a command processor module 903 definedto receive user input for selecting the settings and goals for thenetwork device to be configured, as indicated by arrow 921. The commandprocessor is also defined to receive user input for initiating theverification and testing of the configured network device, as indicatedby arrow 923. Depending of the received user input, the commandprocessor 903 communicates instructions to a system engine module 905,as indicated by arrow 924. The system engine module 905 operates to echothe user input back to the user through the user interface 901, asindicated by arrow 925.

The system engine module 905 also functions to process theuser-specified settings and goals for the network device 803A into oneor more formats that can be correlated with the content of the knowledgedatabase 601. The system engine module 905 then determines the type ofinformation that should be retrieved from the knowledge database toaddress each of the user-specified setting and goals for the networkdevice 803A. Based on the type of information that should be retrievedfrom the knowledge database, the system engine module 905 formulatesappropriate database access requests and communicates the databaseaccess requests to a database command processor module 907, as indicatedby arrow. The database command processor module 907 converts thereceived database access requests into corresponding database querycommands and queries the knowledge database 601, as indicated by arrow929.

Query results generated by database query commands are transmitted fromthe knowledge database 601 to a database results processor module 909,as indicated by arrow 931. The database results processor module 909functions to place the query results into a format that is suitable forcommunication to the system engine module 905, as indicated by arrow933. Once the system engine module 905 receives the query results fromthe knowledge database 601, the system engine module 905 determineswhich network device configuration settings are optimal for satisfyingthe user-specified setting and goals. Then the optimal configurationsettings are communicated to a network device configuration generator911 module, as indicated by arrow 935. The network device configurationgenerator 911 module functions to translate the optimal configurationsettings to a particular brand/model of the network device 803A beingconfigured based on the syntax and command structure that is understoodby the particular network device 803A. The translated configurationsettings generated by the network device configuration generator 911 canbe stored in persistent storage 805, as indicated by arrow, or can beused to configure the network device 803A, as indicated by arrow 939.

The system engine module 905 is also capable of directing a simulationengine module 913 to perform a simulation of the network device 803Aperformance based on the network device configuration settings that aredetermined to be optimal for satisfying the user-specified setting andgoals, as indicated by arrow 941. In one embodiment, the simulationengine module 913 will use test results stored in the knowledge database601 to simulate the performance of the network device 803A. Thesimulation engine module 913 is further defined to communicate thesimulation results to the network engineer 101 through the userinterface 901, as indicated by arrow 943.

The system engine module 905 is also capable of directing a test andverification engine 915 to perform verification and testing of thenetwork device 803A, as indicated by arrow 945. In a manner consistentwith the previously described method of FIG. 7, the test andverification engine 915 is defined to communicate logical settings andcommands to the network device configuration generator module 911, asindicated by arrow 947, wherein the logical settings and commands mayinclude instructions for generating and transmitting appropriate testtraffic through the network device 803A. The network deviceconfiguration generator module 911 functions to translate thesettings/command received from the test and verification engine module915 to the particular brand/model of the network device 803A beingtested based on the syntax and command structure that is understood bythe particular network device 803A. Then, the test settings/commands aretransmitted from the network device configuration generator module 911to the network device 803A, as indicated by arrow 939. The test andverification engine module 915 also operates to echo the testsettings/commands back to the user through the user interface 901, asindicated by arrow 949. In another embodiment, to perform verification,it may be an option to communicate to 803B or 803C to help generatetraffic into 803A.

During verification and testing, statistical data regarding the internaloperations of the network device 803A are communicated from the networkdevice 803A to a network device results interpreter module 917 withinthe network monitoring tool 111, as indicated by arrow 951. The networkdevice results interpreter module 917 functions to process thestatistical data received from the network device 803A into a form thatcan be correlated to the configuration settings of the network device803A. The processed statistical data is then communicated from thenetwork device results interpreter module 917 to a correlation engine919, as indicated by arrow. The correlation engine 919 is capable ofaccessing the configuration settings of the network device 803A storedon the persistent storage device 805, as indicated by arrow 955. Thecorrelation engine 919 functions to evaluate the performance of thenetwork device 803A as represented by the statistical data to theexpected performance of the device as defined by the configurationsettings. Based on the actual-to-expected network device performanceevaluation results, the correlation engine 919 is capable of determiningwhether the network device 803A performance is acceptable. Thecorrelation engine 919 is further defined to convey the processedstatistical data and performance evaluation results to the networkengineer 101 through the user interface 901, as indicated by arrow 957.

FIG. 10 is an illustration showing the interactions present inperforming the testing/verification process described in operations 713through 721 of the method of FIG. 7, in accordance with one embodimentof the present invention. The network engineer 101 initiates the testingand verification process by communicating appropriate commands to thenetwork configuration tool 801, as indicated by arrow (4.1). Asindicated by arrows (4.2), the network configuration tool 801 functionsto program the network devices 803A, 803B, and 803C to generate testtraffic to validate operations of one or more of the configured networkdevices 803A, 803B, and 803C. Although the example of FIG. 10 indicatesthe presence of three network devices 803A, 803B, and 803C, it should beappreciated that the testing and verification process can be performedusing any number of network devices. For example, the testing can beperformed by transmitting normal network traffic through one networkdevice.

As the test traffic is transmitted through the one or more networkdevices (803A, 803B, 803C), the network monitoring tool 111 retrievesmeasurement data, i.e., statistical performance data, from the one ormore network devices, as indicated by arrows (4.4). The networkmonitoring tool 111 functions to display the resulting measurement dataand expected behavior of the one or more network devices (803A, 803B,803C) to the network engineer 101, as indicated by arrow (4.5).Additionally, an optional operation can be performed to store theresulting measurement data and expected behavior of the one or morenetwork devices (803A, 803B, 803C) in the knowledge database 601, asindicated by arrow (4.6), to further expand the depth of performancedata characterized by the knowledge database 601.

FIG. 11 shows a system 1100 for visualizing a network topology andnetwork flows over the network topology, in accordance with oneembodiment of the present invention. In the system 100, network flowrecords are acquired and assembled in a network topology based view tocreate network flow visualization over the network topology. Forpurposes of description, an example network 1102 is shown to includenetwork devices 1104 and their corresponding interfaces 1101. It shouldbe understood that the configuration of the network 1102 in FIG. 11 isprovided by way of example, and in no way represents any type oflimitation on the network configuration to which the system 1100 can beapplied. It should be understood that the system 1100 can be applied toessentially any type and configuration of network.

A network topology includes the network devices 1104, interfaces 1101 ofthe network devices 1104, and links 1103 between the various interfaces1101. The system 1100 is defined to provide network flow visualizationacross the network topology as a layered view at the system level andinside the device level. The system level view is a network topologybased view including one or more network devices and their interfacesconnected together based on network connections. The device level viewis a network flow view inside of a given device showing ingress andegress of network flows and how network flows are routed/switched withinthe given device.

The system 1100 is defined to communicate with the various networkdevices 1104, as indicated by arrows 1123. In various embodiments, thiscommunication can be conducted over wired links, wireless links, or acombination thereof. The system 1100 includes a device informationmanagement module 1105 that is defined to acquire device configurationdata from the devices 1104 within the network 1102. The deviceconfiguration data acquired from a given device 1104 provides forunderstanding of major logical and physical interfaces on the givendevice 1104. The various network devices 1104 can include routers,switches, network appliances (that are network flow capable), securityappliances, and any other network device that can allow applications toread or receive network flow information.

The device information management module 1105 is defined to generate adevice information table 1107 that includes relevant information for thevarious devices 1104 within the network 1102. FIG. 12 shows an exampledevice information table 1107 that may be generated by the deviceinformation management module 1105, in accordance with one embodiment ofthe present invention. The example device information table 1107includes an identification of each interface 1101 within each device1104. For each identified interface 1101, the example device informationtable 1107 also includes a name, a type, an address, and a subnet mask.It should be understood, however, that the particular informationincluded in the device information table 1107 can vary in differentembodiments, so long as the various network devices 1104 and theirinterfaces 1101 through which network flows travel can be uniquelyidentified.

The system 1100 also includes a network visualization module 1109defined to analyze the acquired device configuration data as compiled inthe device information table 1107 to identify the interfaces 1101 ofeach network device 1104 and the subnets to which the interfaces 1101connect. The network visualization module 1109 operates to create anetwork topology by reading the configuration of each network device1104, and by determining the physical and logical interfaces 1101 thatexist, the subnets to which these interfaces 1101 interface, and theaddresses of these interfaces 1101. The network visualization module1109 is further defined to render in a visual display of a computersystem, a network topology visualization 1113 that includes a topologyview of the network 1102, including graphical representations of thedevices 1104, the interfaces 1101 within the devices 1101, and variousconnections between the interfaces 1101 and subnets. Logical interfacessuch as router loopback, null interface, local interface, VLANinterface, tunnels, etc., are also depicted in the network topologyvisualization 1113. For tunnels, the logical connection across thesystem to the far end-point is depicted as well as the tunnel'sassociated physical interface within the router.

FIG. 13 shows an example network topology visualization 1113 within agraphical user interface (GUI) 1300 of the system 1100, in accordancewith one embodiment of the present invention. Generation and operationof the GUI 1300 is provided by the network visualization module 1109.The GUI 1300 includes a first display region 1303 within which thenetwork topology visualization 1113 is visually rendered. Networkdevices 1104A-1104C are shown as large circles. Interfaces within thedevices 1104A-1104C are shown as small circles. For example, the device1104A is shown to include interfaces 1104A1-1101A5, the device 1104B isshown to include interfaces 1101B1-1101B8, and the device 1104C is shownto include interfaces 1101C1-1101C7.

Each network device 1104A-1104C and each interface therein1101A1-1101A5, 1101B1-1101B8, 1101C1-1101C7 is labeled. Also, subnets1301A-1301I to which the various network devices 1104A-1104C areconnected are depicted within the network topology visualization 1113.Line segments indicating network connections are drawn between thevarious subnets 1301A-1301I and the interfaces of the devices1104A-1104B to which they are connected. In one embodiment, values aredisplayed above and below each interface 1101A1-1101A5, 1101B1-1101B8,1101C1-1101C7 to indicate the interface's input and output bandwidths,respectively.

The GUI 1300 also includes a second display region 1305 within which aninteractive hierarchical view of the network 1102 is displayed. Theinteractive hierarchical view shows each device 1104A-1104C and itsinterfaces 1101A1-1101A5, 1101B1-1101B8, 1101C1-1101C7 within thenetwork 1102. Selection within the hierarchical view of a particulardevice 1104A-1104C or a particular interface therein, will cause theview in the first display region 1303 to zoom into the selected device.The GUI 1300 also includes a number of controls 1307 for navigatingaround the network topology visualization 1113 shown in the firstdisplay region 1303. These controls 1307 can include a selectioncontrol, a network flow toggle control, a pan control, a zoom outcontrol, and/or a zoom in control, among others.

With reference back to FIG. 11, the system 1100 also includes a networkflow collection management module 1115 defined to acquire network flowrecords from each device 1104 within the network 1102. The network flowrecords acquired from a given network device 1104 indicates the ingressand egress interfaces for network flows through the given network device1104. As used herein, a network flow record corresponds to a record ofnetwork traffic flow information stored within a network device. Forexample, a network flow record may be generated for each packet ofnetwork traffic that is forwarded within a router or switch. The contentof the network flow record can include the IP source address, the IPdestination address, the source port, the destination port, the ToS bytevalue, the ingress interface identifier, the egress interfaceidentifier, the packet size in bytes, among other items of informationconcerning transmission of packets through a network.

Network flow records are stored within one of a number of formats withina given network device, depending on the type/manufacturer of the givennetwork device. For example, Cisco and some other network devicemanufacturers generate and store network flow records within theirdevices in accordance with a structured format known as NetFlow. Otherdevices may use a network flow record format known as sFlow, which is anetworking community standard that is similar to NetFlow except that itis based on sampled network flow information. Still other networkdevices may use a network flow record format known as IPFIX (IP FlowInformation Export), which is an open standard specification forexchanging IP traffic flow information. IPFIX is very similar to NetFlowbut is supported by the IETF. Also, network devices manufactured byJuniper Networks, Inc., may use a network flow record format known asJ-Flow. It should be understood that the network flow collectionmanagement module 1115 of the system 1100 is defined to understand eachnetwork flow record format utilized by the various devices 1104 of thenetwork 1102, such that accurate network flow records can be acquiredfrom each device 1104 within the network 1102. Additionally, as new ormodified network flow record formats are deployed, the network flowcollection management module 1115 can be updated accordingly.

The network flow collection management module 1115 is defined togenerate a device flow table 1117 that includes data for network flowrecords acquired from the various network devices 1104. FIG. 14 shows anexample device flow table 1117, in accordance with one embodiment of thepresent invention. In some instances, information for a given networkflow through a device is separated into two records: 1) a first recordfor how the network flow entered the device, and 2) a second record forhow the network flow exited the device. If the network flow is separatedinto two records as such, then the two records can be merged into onefor subsequent visualization. Using the network flow information onspecific ingress and egress interfaces of a given device, switching ofthe network flow within the given device can be visualized.

The system 1100 further includes a network flow correlation module 1119define to correlate separate network flow records acquired fromdifferent network devices, as stored in the device flow table 1117,together into a common network flow record, where the separate networkflow records share a common source address and a common destinationaddress. Thus, the common network flow record generated by thecorrelation module 1119 specifies transmission path segments of a singlecommunication through the network. The correlation module 1119 generatesa global flow table 1121 that stores data for the common network flows.

The correlation module 1119 processes the network flow records acquiredfrom the various network devices 1104 to identify and correlate networktraffic that is identical based on key fields found in the network flowrecords. Typical key fields used to identify and correlate networktraffic are source IP address, destination IP address, source portnumber, destination port number, and IP header DSCP marking. When thevalues in the above-mentioned key fields of the network flow recordsmatch, the network flow records are identified as being part of the samenetwork communication.

FIG. 15 shows an example global flow table 1121 based on the exampledevice flow table 1117 of FIG. 14, in accordance with one embodiment ofthe present invention. It should be understood that in variousembodiments, the global flow table 1121 may include more or lessinformation than what is shown in FIG. 15, so long as sufficientinformation is stored in the global flow table 1121 to enablereproduction of how various network communications traverse betweendevices and their interfaces within the network.

Network flow records indicate the ingress and egress interface of thenetwork flow within each device. Using this ingress and egress interfacedata, portions of a given network flow can be stitched together toresemble one continuous network flow across the network, indicatingwhere the network flow enters and exits each network device andassociated interface across the network.

The network visualization module 1109 is defined to render each commonnetwork communication flow over the topology view in the first displayregion 1303 of the GUT 1300 by displaying an arrow for each transmissionpath segment traversed by the common network communication through thenetwork. When multiple common network communication flows aresimultaneously rendered, separate ones of the multiple common networkcommunication flows can be respectively depicted by arrows of commoncharacteristic, e.g., common color.

FIG. 16A shows an example of the GUI 1300 depicting common networkcommunication flows over the topology view in the first display region1303, in accordance with one embodiment of the present invention. Thenetwork flows are visualized by showing the source and destinationaddress as the endpoints and by drawing a number of arrows 1601extending through the network between the source and destinationaddresses. More specifically, an arrow is drawn from a source address toa subnet cloud. Then, an arrow is drawn from the subnet cloud to aningress interface of a network device. Then, an arrow is drawn throughthe network device from the ingress interface to an egress interface.Then, if necessary, additional arrows are drawn to another subnet cloud,and on to another network device, and through the other network device,etc. Ultimately, an arrow is drawn from a network device to thedestination address. Some network flows will get terminated within arouter to which it is destined or within which it is blocked. Thesenetwork flows will show their termination point within the local or nullinterface within the router.

The key fields used to identify and correlate network flow recordswithin the global flow table 1121 can be selected to aggregate anddisplay network flows in various ways. For example, selection of sourceIP address and destination IP address as the key fields, directs thenetwork visualization module 1109 to aggregate network flow records thatshare common source and destination IP addresses. Essentially any typeof network flow aggregation or parsing can be done through particularselections of key fields in the network flow records of the global flowtable 1121.

It should be understood that the system 1100 is defined to acquirenetwork flow records from the various network devices 1104, process theacquired network flow records through the network flow correlationmodule 1119, and render the corresponding aggregated networkcommunication flows within the GUI 1300 in essentially real-time. In oneembodiment, network flow visualization is created based on network flowrecords that are polled, rather than scheduled, so as to get moreaccurate real-time visualization of what is happening in the network1102.

Correlation of network flows from device-to-device requires some storageof network flow data, as the arrival of network flow data at thecorrelation module 1119 from different devices can vary in time,depending on the techniques used to gather the network flow data. Also,caching of network flow data may be required to prevent premature lossof the network flow data before it can be visually rendered in the GUI1300. For example, some devices send the network flow data when thenetwork flow has actually terminated. In this case, the correlationengine may need to cache the network flow data. Also, in one embodiment,cached network flow data can be allowed to expire (and be deleted) aftera specified period of time.

The GUI 1300 and underlying network visualization module 1109 is definedto enable visual exploration and analysis of the acquired and processednetwork flow data. FIG. 16B shows an example of how a particular networkcommunication flow can be selected and identified within the GUI 1300,in accordance with one embodiment of the present invention.Specifically, the darker arrows 1603 correspond to the selected networkcommunication flow that originated at source IP address 10.0.1.1 andterminated at destination IP address 192.0.1.1. In one embodiment,selection of a particular network communication flow can be done by wayof a user input device such as a mouse. In another embodiment, selectionof a particular network communication flow can be made from a listing ofthe displayed network communication flows.

FIG. 16C shows an example of how the GUI 1300 can be operated to zoom inon a particular network device, in accordance with one embodiment of thepresent invention. FIG. 16C also shows a feature of the GUI 1300 fordisplaying information 1605 about a particular selected networkcommunication flow 1607. FIG. 16D shows an example of how the GUT 1300can be operated to display a device level view of a particular networkdevice 1609, in accordance with one embodiment of the present invention.A user can select the particular device 1609 within the hierarchicalview of the network within the second display region 1305. An isolatedview of the selected device 1609 is rendered in the first display region1303 showing the device 1609 along with its interfaces and arrowsrepresenting the various network flows associated with the device 1609.The device level view also provides a tabular listing of data for thenetwork flows associated with the device 1609 within a display region1611.

The network visualization module 1109 provides for filtering of thedisplayed network flows based on various network flow parameters such asDSCP, port, IP address, layer 4 protocol, bit rate range, byte range,among others. FIG. 17A shows a control GUI 1701 for defining, saving,and applying a network flow parameter filter, in accordance with oneembodiment of the present invention. The network visualization module1109 also provides for customization of how the network topology andvarious network flows are shown in the GUI 1300.

FIGS. 17B-17F show control GUIs for applying selected colors toparticular network topology and flow parameter ranges to facilitatevisual evaluation of the network and flows therein, in accordance withvarious embodiments of the present invention. FIG. 17B shows a colormapping control GUI 1703 for applying various colors to different rangesof the DSCP parameter. FIG. 17C shows a color mapping control GUI 1705for applying various colors to different ranges of the port parameter.FIG. 17D shows a color mapping control GUI 1707 for applying variouscolors to different ranges of the IP address parameter. FIG. 17E shows acolor mapping control GUI 1709 for applying various colors to differentranges of the byte count parameter. FIG. 17F shows a color mappingcontrol GUI 1711 for applying various colors to different ranges of therate parameter.

Network flow information that is gathered by the system 1100 over timecan be stored in a database. This historical network flow informationcan be analyzed through various methods and data mining techniques. Inone embodiment, historical displays can be generated within the GUI 1300to show trending in a spatial manner within the network topology view.Network flow information can be used to show internal paths taken by agiven flow inside routers, switches, and other network devices withinthe network topology view. In one embodiment, historical changes innetwork flows can be shown by binning network flow information intotemporal bins. Also, historical network flows can be correlated acrossnetwork devices using network flow keys. Once correlated, a givenhistorical network flow can be visualized as a single flow across thenetwork devices through which it traveled.

Historical network flow information can be sorted, filtered, grouped,and/or colored using various classification methods based on variousinformation from different packet layers, including packet layers 2, 3,4, etc. Also, in one embodiment, historical network flows for aparticular time of interest can be rendered over the network topologyview within the GUI 1300 by way of a slider control that allowsselection of a particular time period. Additionally, an automaticplayback feature is provided to enable animation of historical networkflows over time within the visual context of the network topology view.

It should be appreciated that the system 1100 for network topology andflow visualization provides many useful features. For example, thesystem 1100 includes a feature to enable creation of lists such thatnetwork addresses that match are displayed differently by color, name,etc. Also, the system 1100 provides for aggregation of network flowsinto categories. The system 1100 provides for display of network flowstatus, device status, and/or interface status by color and/orstatistics. The system 1100 also provides various ways to filter, color,and/or search the network flow data for visualization within the GUI1300. Additionally, the system 1100 provides for real-time informationof network flows, such as bandwidth usage.

The system 1100 is also defined to visually display routing informationon top of the network topology view within the GUT 1300. Routinginformation can be gathered by reading routing table entries directlyfrom the various network devices. It should be appreciated that therouting table entries that are read may not be the same routing tableentries that are advertised externally. This visualization feature mayshow route entries coming out of a given interface that the route entrywould process packets toward.

The system 1100 is also defined to visually display artificial networktraffic generation logical connections on top of the network topologyview. Also, artificial network traffic generation, such as IPSLA (IPService Level Agreement) statistics can be visually displayed on top ofthe network topology view within the GUI 1300. The system 1100 alsoprovides for visual identification of layer 2 network flows within aVLAN by MAC or VLAN tag parameters, or other relevant parameters. Thesystem 1100 further provides for display of a virtualization of a VLANon top of the network topology view within the GUI 1300, includingidentification of the VLAN port and device membership within thenetwork.

Additionally, the network visualization module 1109 can be defined togenerate ladder diagrams showing back and forth transaction of networkflows for particular applications. This is accomplished by using thenetwork flow data key fields in various ways. For example, in oneembodiment, the key fields are set as the source IP address, destinationIP address, source port, destination port, and TCP flag field. In thisembodiment, a new network flow would be created for each TCP flagchange.

It should be understood that the system 1100 for network topology andflow visualization is particularly well-suited for use in conjunctionwith the method of FIG. 7 for optimally configuring a network device byutilizing the knowledge database developed according to the method ofFIG. 1. In particular, the system 1100 can be utilized to visuallymonitor and evaluate network flows through the DUT 205 analyzed in thetest system 200, and/or through the network device installed inoperation 701.

FIG. 18 shows a flowchart of a method for visualizing a networktopology, in accordance with one embodiment of the present invention.The method includes an operation 1801 for acquiring device configurationdata from a number of network devices through which network flows are tobe transmitted. In one embodiment, a device information table isgenerated to include the acquired device configuration data, and thedevice information table is stored on a computer readable storagemedium. The method also includes an operation 1803 for analyzing theacquired device configuration data to identify one or more interfaces ofeach of the number of network devices, and to identify subnets to whichthe one or more interfaces connect.

The method further includes an operation 1805 for rendering in a visualdisplay of a computer system a number of device objects corresponding tothe number of network devices. The method also includes an operation1807 for rendering in the visual display a number of interface objectswithin each of the number of device objects. Each interface objectrepresents a particular identified interface of the network device thatcorresponds to the rendered device object. In one embodiment, theoperation 1805 includes displaying and labeling a large geometric shapefor each device object. Also, in one embodiment, the operation 1807includes displaying and labeling a small geometric shape for eachinterface object within the large geometric shape of its device object.In one embodiment, the small and large geometric shapes are depicted assmall and large circles, respectively. The method can also include anoperation for rendering a first value above each interface objectindicating an input bandwidth of the interface object, and rendering asecond value below each interface object indicating an output bandwidthof the interface object.

The method further includes an operation 1809 for rendering in thevisual display a number of subnet objects corresponding to theidentified subnets. An operation 1811 is also provided for rendering inthe visual display line segments extending between interface objects andsubnet objects. The line segments represent network connections overwhich network flows are to be transmitted. Additionally, in oneembodiment, an operation is performed to render in the visual display ahierarchical view of the number of network devices and the interfaceswithin the number of network devices. Also in this embodiment, uponselection of a particular network device in the hierarchical view, anisolated view of the particular selected network device is rendered inthe visual display.

FIG. 19 shows a flowchart of a method for visualizing a network flowover a network topology, in accordance with one embodiment of thepresent invention. The method includes an operation 1901 for generatinga topology view of a network on a visual display of a computer system.The topology view includes subnet objects, network device objects, andinterface objects within the network device objects. Generation of thetopology view includes labeling each of the subnet objects, networkdevice objects, and interface objects.

The method also includes an operation 1903 for acquiring network flowrecords from each device within the network. In one embodiment, thenetwork flow records for each device correspond to communication packetdata records. Each communication packet data record includes an IPsource address, an IP destination address, a source port, and adestination port. The method further includes an operation 1905 forcorrelating separate network flow records acquired from differentdevices in the network together into a common network flow record. Eachof the separate network flow records shares a common source address anda common destination address. Also, the common network flow recordspecifies transmission path segments of a communication through thenetwork.

The method also includes an operation 1907 for rendering in the visualdisplay the common network flow over the topology view of the network bydisplaying an arrow for each transmission path segment traversed by thecommunication through the network. Arrows for transmission path segmentstraversed by a given communication through the network are depicted in alike manner to indicate that the arrows are associated with the givencommunication. Arrows associated with different communications throughthe network are depicted differently to visually differentiate betweenthe different communications. In one embodiment, the method alsoincludes an operation for selecting an arrow for a given transmissionpath segment, and conspicuously modifying a visual display of all arrowsassociated with the communication through the network within which thegiven transmission path segment is included.

Based on the foregoing, it should be appreciated that the system 1100for network topology and flow visualization provides advanced systemlevel network flow visualization with detailed internal router andinterface flow visualizations. By way of the system 1100, networkengineers are able to quickly set up and view network flow information,e.g., NetFlow data, on their specific networks. The system 1100 providesa network topology view with live network flow activity displayed overthe network topology view. By way of the network topology view, a usercan quickly drill down to individual devices and/or interfaces to obtaincorresponding detailed information. The network topology and flow viewsprovided by the system 1100 enable quick and easy identification oftrouble spots on the network, such as congested devices and/orinterfaces. Additionally, the system 1100 enables clear visualobservation of the results of applying different network and routersettings, such as the effects of applying routing changes on networktraffic and flows.

With the above embodiments in mind, it should be understood that thepresent invention may employ various computer-implemented operationsinvolving data stored in computer systems. These operations are thoserequiring physical manipulation of physical quantities. Usually, thoughnot necessarily, these quantities take the form of electrical ormagnetic signals capable of being stored, transferred, combined,compared, and otherwise manipulated. Further, the manipulationsperformed are often referred to in terms, such as producing,identifying, determining, or comparing.

Any of the operations described herein that form part of the inventionare useful machine operations. The invention also relates to a device oran apparatus for performing these operations. The apparatus may bespecially constructed for the required purpose, such as a specialpurpose computer. When defined as a special purpose computer, thecomputer can also perform other processing, program execution orroutines that are not part of the special purpose, while still beingcapable of operating for the special purpose. Alternatively, theoperations may be processed by a general purpose computer selectivelyactivated or configured by one or more computer programs stored in thecomputer memory, cache, or obtained over a network. When data isobtained over a network the data maybe processed by other computers onthe network, e.g., a cloud of computing resources.

The embodiments of the present invention can also be defined as amachine that transforms data from one state to another state. The datamay represent an article, that can be represented as an electronicsignal and electronically manipulate data. The transformed data can, insome cases, be visually depicted on a display, representing the physicalobject that results from the transformation of data. The transformeddata can be saved to storage generally, or in particular formats thatenable the construction or depiction of a physical and tangible object.In some embodiments, the manipulation can be performed by a processor.In such an example, the processor thus transforms the data from onething to another. Still further, the methods can be processed by one ormore machines or processors that can be connected over a network. Eachmachine can transform data from one state or thing to another, and canalso process data, save data to storage, transmit data over a network,display the result, or communicate the result to another machine.

The invention can also be embodied as computer readable code on acomputer readable medium. The computer readable medium is any datastorage device that can store data which can thereafter be read by acomputer system. Examples of the computer readable medium include harddrives, network attached storage (NAS), read-only memory, random-accessmemory, CD-ROMs, CD-Rs, CD-RWs, DVDs, magnetic tapes, and other opticaland non-optical data storage devices. The computer readable medium canalso be distributed over a network of coupled computer systems so thatthe computer readable code is stored and executed in a distributedfashion.

Although the foregoing invention has been described in some detail forpurposes of clarity of understanding, it will be apparent that certainchanges and modifications can be practiced within the scope of theappended claims. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the invention is notto be limited to the details given herein, but may be modified withinthe scope and equivalents of the appended claims.

What is claimed is:
 1. A method for visualizing a network datacommunication flow over a network topology, comprising: obtaining deviceconfiguration data from device information tables of a plurality ofnetwork devices within a network; analyzing the obtained deviceconfiguration data to identify interfaces of each of the plurality ofnetwork devices, the interfaces including physical interfaces andlogical interfaces; generating a topology view of the network on avisual display of a computer system, wherein the topology view includessubnet objects, network device objects, physical interface objectswithin the network device objects, and logical interface objects withinsome network device objects; acquiring a plurality of network datacommunication flow records from each of the plurality of network deviceswithin the network for a specified time period, wherein each of theplurality of network data communication flow records is associated witha corresponding one of the plurality of network devices, and whereineach of the plurality of network data communication flow recordsincludes information about network traffic flowing through thecorresponding one of the plurality of network devices to which thenetwork data communication flow record is associated, and wherein eachof the plurality of network data communication flow records is generatedand stored by the corresponding one of the plurality of network devicesto which the network data communication flow record is associated, andwherein each of the plurality of network data communication flow recordsis generated and stored separate from the network traffic flowingthrough the corresponding one of the plurality of network devices towhich the network data communication flow record is associated, andwherein each of the plurality of network data communication flow recordsincludes data fields for 1) an identifier of an ingress interfacethrough which the network traffic entered the corresponding one of theplurality of network devices to which the network data communicationflow record is associated, and 2) an identifier of an egress interfacethrough which the network traffic exited the corresponding one of theplurality of network devices to which the network data communicationflow record is associated or an identifier of an internal interface atwhich the network traffic terminated within the corresponding one of theplurality of network devices to which the network data communicationflow record is associated, and 3) an internet protocol source addressfor the network traffic, and 4) an internet protocol destination addressfor the network traffic, and 5) a source port for the network traffic,and 6) a destination port for the network traffic; correlating separateones of the plurality of network data communication flow recordsacquired from different ones of the plurality of network devices in thenetwork based on content of the data fields so as to create a commonnetwork data communication flow record as a combination of thecorrelated separate ones of the plurality of network data communicationflow records, wherein each of the separate ones of the plurality ofnetwork data communication flow records within the common network datacommunication flow record has 1) identical content in the data field forthe internet protocol source address for the network traffic, and 2)identical content in the data field for the internet protocoldestination address for the network traffic, and 3) identical content inthe data field for the source port for the network traffic, and 4)identical content in the data field for the destination port for thenetwork traffic; repeating the correlating of separate ones of theplurality of network data communication flow records based on content ofthe data fields so as to create a plurality of common network datacommunication flow records; aggregating some of the plurality of commonnetwork data communication flow records based on identical content inone or more data fields of the plurality of common network datacommunication flow records to create an aggregated network communicationflow record-; and rendering in the topology view of the network on thevisual display a graphical representation of the aggregated networkcommunication flow record in lieu of rendering graphical representationsof the plurality of common network data communication flow recordsrepresented by the aggregated network communication flow record, thegraphical representation of the aggregated network communication flowrecord including one or more arrows to represent a data communicationpath traversed through some of the plurality of network devices bynetwork flows represented by the aggregated network communication flowrecord, the graphical representation of the aggregated networkcommunication flow record including at least one arrow extending betweentwo internal interfaces of a given one of the plurality of networkdevices.
 2. A method for visualizing a network data communication flowover a network topology as recited in claim 1, wherein the one or morearrows of the graphical representation of the aggregated networkcommunication flow record are depicted in a like manner.
 3. A method forvisualizing a network data communication flow over a network topology asrecited in claim 1, wherein arrows associated with different aggregatednetwork communication flow records are depicted differently to visuallydifferentiate between the different aggregated network communicationflow records.
 4. A method for visualizing a network data communicationflow over a network topology as recited in claim 1, further comprising:selecting one or more key data fields within the plurality of commonnetwork data communication flow records for use in the aggregating tocreate the aggregated network communication flow record.
 5. A method forvisualizing a network data communication flow over a network topology asrecited in claim 1, further comprising: selecting an arrow for a givenaggregated network communication flow record; and conspicuouslymodifying a visual display of all arrows associated with the aggregatednetwork communication flow record within which the selected arrow isincluded.
 6. A method for visualizing a network data communication flowover a network topology as recited in claim 1, further comprising:selecting one or more filter settings for network data communicationflow parameters and associated ranges by which network datacommunication flow records are to be filtered for display; and renderingarrows for network data communication transmission path segments thatsatisfy the selected filter settings.
 7. A computer system forvisualizing a network data communication flow over a network topology,comprising: a device information management module defined to obtaindevice configuration data from device information tables of a pluralityof network devices within a network; a network visualization moduledefined to analyze the obtained device configuration data to identifyinterfaces of each of the plurality of network devices, the interfacesincluding physical interfaces and logical interfaces, and to identifysubnets to which the interfaces connect, and further defined to renderin a visual display a topology view of the network including graphicalrepresentations of the subnets, the network devices, the physicalinterfaces within the network devices, the logical interfaces within thenetwork devices; a network flow collection management module defined toacquire a plurality of network data communication flow records from eachof the plurality of network devices within the network for a specifiedtime period, wherein each of the plurality of network data communicationflow records is associated with a corresponding one of the plurality ofnetwork devices, and wherein each of the plurality of network datacommunication flow records includes information about network trafficflowing through the corresponding one of the plurality of networkdevices to which the network data communication flow record isassociated, and wherein each of the plurality of network datacommunication flow records is generated and stored by the correspondingone of the plurality of network devices to which the network datacommunication flow record is associated, and wherein each of theplurality of network data communication flow records is generated andstored separate from the network traffic flowing through thecorresponding one of the plurality of network device to which thenetwork data communication flow record is associated, and wherein eachof the plurality of network data communication flow records includesdata fields for 1) an identifier of an ingress interface through whichthe network traffic entered the corresponding one of the plurality ofnetwork devices to which the network data communication flow record isassociated, and 2) an identifier of an egress interface through whichthe network traffic exited the corresponding one of the plurality ofnetwork devices to which the network data communication flow record isassociated or an identifier of an internal interface at which thenetwork traffic terminated within the corresponding one of the pluralityof network devices to which the network data communication flow recordis associated, and 3) an internet protocol source address for thenetwork traffic, and 4) an internet protocol destination address for thenetwork traffic, and 5) a source port for the network traffic, and 6) adestination port for the network traffic; a network flow correlationmodule defined to correlate separate ones of the plurality of networkdata communication flow records acquired from different ones of theplurality of network devices in the network based on content of the datafields so as to create a common network data communication flow recordas a combination of the correlated separate ones of the plurality ofnetwork data communication flow records, wherein each of the separateones of the plurality of network data communication flow records withinthe common network data communication flow record has 1) identicalcontent in the data field for the internet protocol source address forthe network traffic, and 2) identical content in the data field for theinternet protocol destination address for the network traffic, and 3)identical content in the data field for the source port for the networktraffic, and 4) identical content in the data field for the destinationport for the network traffic, the network flow correlation moduledefined to repeat the correlating of separate ones of the plurality ofnetwork data communication flow records based on content of the datafields so as to create a plurality of common network data communicationflow records, the network flow correlation module defined to aggregatesome of the plurality of common network data communication flow recordsbased on identical content in one or more data fields of the pluralityof common network data communication flow records to create anaggregated network communication flow record, and wherein the networkvisualization module is defined to render in the topology view of thenetwork on the visual display a graphical representation of theaggregated network communication flow record in lieu of renderinggraphical representations of the plurality of common network datacommunication flow records represented by the aggregated networkcommunication flow record, the graphical representation of theaggregated network communication flow record including one or morearrows to represent a data communication path traversed through some ofthe plurality of network devices by network flows represented by theaggregated network communication flow record, the graphicalrepresentation of the aggregated network communication flow recordincluding at least one arrow extending between two internal interfacesof a given one of the plurality of network devices.
 8. A computer systemfor visualizing a network data communication flow over a networktopology as recited in claim 7, wherein the network flow collectionmanagement module is defined to understand each network datacommunication flow record format utilized by each of the plurality ofnetwork devices within the network, wherein different ones of theplurality of network devices can utilize different network datacommunication flow formats.
 9. A computer system for visualizing anetwork data communication flow over a network topology as recited inclaim 7, wherein the network flow correlation module is defined tocombine a first network data communication flow record for how a givennetwork data communication flow entered a device with a second networkdata communication flow record for how the given network datacommunication flow exited the device so as to create a single networkdata communication flow record for the given network data communicationflow through the device.
 10. A computer system for visualizing a networkdata communication flow over a network topology as recited in claim 7,wherein the network flow collection management module is defined toenable polling of network data communication flow records to facilitatereal-time rendering of network data communication flows over thetopology view of the network.
 11. A method for visualizing a networkdata communication flow over a network topology as recited in claim 1,wherein generating the topology view of the network on the visualdisplay of the computer system includes rendering in the visual displayline segments extending between physical interface objects and subnetobjects, wherein the line segments represent network connections.
 12. Amethod for visualizing a network data communication flow over a networktopology as recited in claim 11, wherein each of the network deviceobjects is displayed as a large geometric shape within the topology viewof the network.
 13. A method for visualizing a network datacommunication flow over a network topology as recited in claim 12,wherein each of the physical interface objects and logical interfaceobjects is displayed as a small geometric shape within the largegeometric shape of its network device object.
 14. A method forvisualizing a network data communication flow over a network topology asrecited in claim 13, wherein the small and large geometric shapes aresmall and large circles respectively.
 15. A method for visualizing anetwork data communication flow over a network topology as recited inclaim 11, further comprising: rendering in the visual display a firstvalue above each physical interface object indicating an input bandwidthof the physical interface object; and rendering in the visual display asecond value below each physical interface object indicating an outputbandwidth of the physical interface object.
 16. A method for visualizinga network data communication flow over a network topology as recited inclaim 11, further comprising: rendering in the visual display ahierarchical view of the number of network device objects and thephysical interfaces within the number of network device objects; andupon selection of a particular network device object in the hierarchicalview, rendering in the visual display an isolated view of the particularselected network device object.
 17. A method for visualizing a networkdata communication flow over a network topology as recited in claim 11,further comprising: generating a device information table to include theobtained device configuration data; and storing the device informationtable on a computer readable storage medium.
 18. A method forvisualizing a network data communication flow over a network topology asrecited in claim 1, wherein the topology view includes at least onelogical tunnel connection between logical interface objects in differentnetwork device objects.
 19. A method for visualizing a network datacommunication flow over a network topology as recited in claim 18,wherein generating the topology view of the network includes labelingeach of the subnet objects, network device objects, physical interfaceobjects, logical interface objects, and the at least one logical tunnelconnection.
 20. A method for visualizing a network data communicationflow over a network topology as recited in claim 1, further comprising:storing the plurality of common network data communication flow recordsin a global flow table.
 21. A method for visualizing a network datacommunication flow over a network topology as recited in claim 1,wherein each network data communication flow record is defined in eithera NetFlow format, or an IPFIX (Internet Protocol Flow InformationExport) format, or a combination of NetFlow and IPFIX formats.